UV-B辐射增强对亚历山大藻和赤潮异弯藻种群竞争的影响

通过共培养的方法,研究了亚历山大藻和赤潮异弯藻种群竞争关系对UV-B辐射增强的响应变化．结果表明,不同的接种密度对亚历山大藻和赤潮异弯藻种群竞争有明显的影响．当亚历山大藻(A)和赤潮异弯藻(H)的接种比例为A：H=1：4时,赤潮异弯藻在与亚历山大藻的竞争中占优势;当接种比例为A：H=1：1和A：H=4：1时,亚历山大藻在竞争中占优势．UV—B辐射增强可改变亚历山大藻和赤潮异弯藻种群竞争的关系,使赤潮异弯藻的种群竞争能力降低,使亚历山大藻的种群竞争能力大大提高,从而导致亚历山大藻在处理Ⅱ(A：H=1：1)和处理Ⅲ(A：H=4：1)中的优势地位更加明显．     

中国地表净辐射推算方法的研究

利用我国气象系统现有的50个净辐射站1993-2000年的辐射及相关气象资料,采用5种方法计算地表净辐射月值,结果表明:论文构建的多因子综合法是一种误差最小、精度最高的推算方法,平均相对误差为0.348,4至9月误差在0.20以下,可用于全年各月地表净辐射的推算;其次为Chang Jen_Hu修正式和Penman修正式,平均相对误差都在0.64以下,误差小于0.20的站月数约占半数左右,4至9月误差都在0.25以下,可用于植物生长期间的地表净辐射推算。各种方法推算的平均相对误差,都具有北部地区明显大于南部地区,冬半年（11至2月）明显大于夏半年（3至10月）的时空分布特征。     

中国农业植被净初级生产力模拟(I)——模型的建立与灵敏度分析

以业已建成的稻麦作物净初级生产力模型为基本框架,建立了一个具有普适性的中国农业植被净初级生产力模型(CropC-)。CropC-的模拟对象为占我国农作物总播种面积2/3的水稻、小麦、玉米、棉花、油菜和大豆。该模型包括2个主要功能模块:光合作用和呼吸作用;土壤-作物系统氮素运移。前者综合考虑了环境因子和氮素的影响,后者包括了作物氮素吸收、土壤氮矿化和化肥氮释放。灵敏度分析表明,在输入参数变化±10%时,CropC-对6个主要输入参数响应的敏感性依次为温度>光合有效辐射>大气CO2浓度>土壤全氮含量>施氮量>降水。模型分析表明,气候变暖将降低作物净初级生产力。     

活性炭吸附硫化氢及微波辐照解吸研究

研究了两种活性炭对硫化氢的平衡吸附性能力,并对活性炭床层的穿透性进行了考察;吸附饱和和活性炭在微波辐射的作用下进行解吸。实验表明,解吸效率与微波作用时间及温度有关,在本实验条件下H2S解吸效率达90．1％。     

沸腾液体扩展蒸气爆炸机理及相关计算理论模型研究

剖析了沸腾液体扩展蒸气爆炸 (BLEVE)的发生、发展过程 ,阐述了其机理及相关条件 ,研究并提出了两种BLEVE火球热辐射模拟计算理论模型 ,即近地面和抬升火球模型 ,以及爆炸超压模型。与有关实验结果比较和与已有模型的对比计算表明了所建模型的有效性     

电磁辐射对环境的污染及防护措施

电磁辐射对环境的污染已引起人们的重视 ,早在 196 9就被联合国人类环境会议列为必须严格控制的现代公害之一。论述了电磁辐射的来源、危害及减少电磁辐射是对环境污染的防护措施。对全面了解电磁辐射对环境造成的污染及危害 ,提高自我防护意识具有参考价值     

Fluctuating Asymmetry in Cranial Measurements of East European Voles (Microtus rossiaemeridionalis Ognev, 1924) from the Zone of Radioactive Contamination

Fluctuating asymmetry (FA) in eight cranial measurements was studied in Microtus rossiaemeridionalis voles from two sites of the zone affected by the Totsk Radioactive Trace (TRT) and in the control population. In the affected populations, generalized mean population parameters of FA were significantly higher than in the control and tended to increase in relatively larger animals. The disturbance of ontogenetic homeostasis in voles from the TRT zone probably resulted from environmental stress caused by contamination with radionuclides (primarily plutonium), which entailed irradiation of many vole generations over more than 40 years.     

Water-saving Technologies,Solar Green House and Ecological Rehabilitation in Minqin Oasis of Gansu Province,China

Abstract

Land degradation and desertification have become severe environmental problems in arid areas due to excessive use of water resources. It is urgent to reduce agricultural water use for ecological rehabilitation, which may result in a decrease in agricultural production and farmer’s welfare. This paper focused on the impacts of some main measures including extensions of water-saving irrigation, expanding solar green house and increasing off-farm employment, which are generally recognized to be important to alleviate water shortage and poverty. A bio-economic model is applied taking Minqin Oasis in Gansu Province as a case study site. Simulation results showed that the effect of expanding solar greenhouse was more positive than other ones so it drew more attention. On the view of the different effects between each irrigation zone, mixed policy patterns suitable for them are suggested. In Baqu, expanding solar greenhouse should be the most important, auxiliary with encouraging pipe irrigation. Inversely, with regard to Quanshan, the major attention should be paid to subsidy for pipe irrigation and it would be better to supply the off-farm employment opportunities to the households in Huqu, where the expanding of solar greenhouse should also be summoned. Finally, it should be noted that farmer’s income would only resume to 90% of the current level in the short run by putting more effort into local policies. Thus, the ecological compensation is needed to ensure farmer’s welfare.     

The performance of solar powered desiccant dehumidifier in India: an experimental investigation

The regeneration and adsorption of desiccant wheel for producing the dry air was experimentally investigated. The air needed for regeneration was heated in an evacuated tube solar collector with surface area 4.44 m². The desiccant wheel is regenerated at the temperature in the range of 43.9–72.6°C. The regeneration and adsorption performances are affected by the regeneration temperature, wheel rotation, air flow rate (process and regeneration) and ambient conditions. By comparing the adsorption and regeneration performance at different air flow rate and constant rph, it was found that maximum adsorption and regeneration rates are obtained at air flow rate of 210.789 kg/h. Regeneration temperature directly affects the effectiveness of the desiccant wheel. Maximum desiccant wheel effectiveness of regeneration sector and adsorption sector is obtained at air flow rate of 105.394 kg/h. The regeneration performance of desiccant wheel with evacuated tube solar air collector is suitable for the Indian climate.     

Non-Thermal Effect of Microwave Radiation on Human Brain

Summary This study focuses on an origin of interaction mechanism of microwave radiation with nervous system—quasi-thermal field effect. The microwave field can cause fluctuations and vibration of the charged particles and membranes in tissues. The hypothesis is, that this phenomenon is similar to the effect caused by Brown motion initiated by temperature and results in the same effects without rise in temperature. The electric field of 1 V/cm can introduce disturbance of the thermal equilibrium inside a cell of 10 μm radius, which is equivalent to disturbance produced by temperature rise of 1 K. The hypothesis, that microwave heating should cause an effect independent of the microwave modulation frequency, while field effect depends on modulation frequency, was examined experimentally. The 450 MHz microwave radiation, modulated at 7, 14 and 21 Hz frequencies, power density at the skin 0.16 mW/cm², was applied. The experimental protocol consisted of two series of five cycles of the repetitive microwave exposure at fixed modulation frequencies. Relative changes in EEG theta, alpha and beta rhythms of the group of 13 healthy volunteers were analysed. Analysis of the experimental data shows that: (1) statistically significant changes in EEG rhythms depend on modulation frequency of the microwave field; (2) microwave stimulation causes an increase of the EEG energy level; (3) the effect is most intense at beta1 rhythm and higher modulation frequencies. These findings confirm the quasi-thermal origin of the effect, different from average heating.